fix(core): 跨 crate 小修复 — dto 合并、tracing 补全、死代码清理

- erp-ai: 删除孤立 dto.rs（已合并到子模块）
- erp-core: audit_service tracing 优化
- erp-health: points_handler 补充返回值、alert_engine 修正日志级别
- erp-plugin: host/data_handler/market_handler tracing 统一
- erp-dialysis/event: 移除无用 import
- erp-workflow/executor: tracing 格式统一

crates/erp-workflow/src/engine/executor.rs

@@ -426,7 +426,7 @@ impl FlowExecutor {
                 .await
                 .map_err(|e| WorkflowError::Validation(e.to_string()))?;
 
-            for mut t in consumed_tokens {
+            for t in consumed_tokens {
                 let ver = t.version;
                 let mut active: token::ActiveModel = t.into();
                 active.status = Set("completed".to_string());